Off road vehicles, whether in the military or working trucks, must deal with highly variable soil conditions. Different soil conditions require different tire pressures to optimize traction. There are already Central Tire Inflation Systems (CTIS) that are being used to accurately vary the tire pressure while in the vehicle. However, the driver has top operate the system by using experience and or intuition.
Tire pressure, if adjusted properly, can lead to greater traction and efficiency. The proper pressure for a given tire is highly dependent on the given soil condition, and as soil conditions vary widely, the proper tire pressure can vary widely. For example, sandy and rocky conditions call for a relatively lowered tire pressure, whereas paved roads (which are a major part of the modern battlefield and used by millions of vehicles in the private sector) require a relatively higher tire pressure to ensure good efficiency. The US Army developed the Vehicle Cone Index (VCI) as a metric for directly quantifying the ability of vehicles to traverse soft-soil terrain. In order to ensure minimum soft-soil performance capabilities for their new military vehicles, the US Army has used VCI for many years as a performance specification. But readily measuring the VCI or any parameter that predicts the traction in a moving vehicle has been a long sought need.
There is a need then for a system that will detect when tire pressure is inappropriate or non-optimal and then adjust the tire pressure accordingly. The tire pressure detection can be based on the measurement of the static deflection of the tire. Such a detection system would enhance the capability of the vehicle when driving in harsh off-road conditions.
These needs can be met by the system to be disclosed, which makes use of magnetic coils embedded in the wheel assembly to detect the position of the tire's steel belting and uses the information obtained to adjust the tire pressure through a central tire inflation system.
These needs can also be met by an alternate embodiment system to be disclosed, which makes use of ultrasonic sensors in the wheel assembly to detect the position of the tire's steel belting and uses the information obtained to adjust the tire pressure through a central tire inflation system.